getCachedResponseMetadata

Returns additional metadata for a previously executed successful, request, typically used for debugging issues
where a service isn't acting as expected. This data isn't considered part of the result data returned by an
operation, so it's available through this separate, diagnostic interface.

Response metadata is only cached for a limited period of time, so if you need to access this extra diagnostic
information for an executed request, you should use this method to retrieve it as soon as possible after
executing the request.